Brightwell NeoPhos — balanced phosphate source for ULNS reef aquariums

The Brightwell NeoPhos is a phosphate source for ultra-low nutrient systems where PO₄ has dropped below the biologically useful range. Formulated in the United States by Brightwell Aquatics, it supplies the phosphorus beneficial microbes need to keep absorbing and eliminating organic waste in a reef aquarium running on a probiotic method or carbon dosing.

On a ULNS, a too-low PO₄ blocks biology the same way a too-low NO₃ does — microbial capacity to break down ammonia, nitrite, and nitrate depends on the simultaneous availability of carbon, nitrogen, and phosphorus. NeoPhos brings PO₄ back into the 0.01 to 0.02 ppm target range while the system keeps processing organic excess.

What NeoPhos is for and when to use it

Phosphorus-limited SPS ULNS tanks — corals pale out, tissue recedes because PO₄ is too low for biology to consume excess NO₃.
Unbalanced probiotic routine — NP Pro, Bio S, or similar that has dropped PO₄ below 0.01 ppm and blocked nitrogen uptake.
Heavy Berlin-method tanks — aggressive skimming and very porous rock that have exported all residual PO₄.
ICP correction — an ICP-OES or ICP-MS reading confirming dissolved PO₄ below the reef useful range.

Brightwell official use

NeoPhos has been sold in more than one strength. Always check the bottle label for the number of gallons treated and the ppm ratio — the value printed on your bottle is the only reliable reference.

Test PO₄ and NO₃ with accurate kits or a calibrated digital instrument.
Dose NeoPhos until PO₄ reads approximately 0.02 ppm.
Wait 24 hours, retest.
If concentrations are unchanged, the system is carbon-limited — add Reef BioFuel at 1 mL per 25 US gal.
Keep dosing NeoPhos to maintain PO₄ at 0.01 to 0.02 ppm until NO₃ drops into the target 3 to 5 ppm range.

Specifications

Brand: Brightwell Aquatics (made in the USA)
Available sizes: 250 mL, 500 mL, 2 L, 4 L, 20 L
Composition: purified water and proprietary phosphate salts
Variable concentration: check the label of the bottle received (multiple historical versions)
Intended audience: advanced reef aquarists running ULNS systems

Why choose Brightwell at ReefSolution

Brightwell NeoNitro — the nitrate booster to pair on a ULNS to balance the N:P ratio.
Salifert Phosphate Test Kit — the 0.01 ppm titration kit required to steer NeoPhos without overshoot.
Brightwell MicroBacter7 — the bioculture that uses the added PO₄ to resume its work on ammonia and NO₃.

Frequently asked questions

Why add phosphate to a reef aquarium?

On a ULNS where PO₄ falls below 0.01 ppm, microbial biology lacks phosphorus to take up nitrogen and efficiently remove organic waste. Result: NO₃ stops falling, SPS pale out, the probiotic routine stalls. NeoPhos brings PO₄ back into the Brightwell target range of 0.01 to 0.02 ppm to restart the cycle.

How many ppm does my NeoPhos add per mL?

Brightwell states that multiple NeoPhos concentrations have been sold — the ppm/gal value is printed on your bottle's label. That is the only reliable reference for calculating your dose.

What if PO₄ does not move after a dose?

Retest 24 hours later. If PO₄ is unchanged, Brightwell states the system is carbon-limited — microbes lack organic carbon to take up the added phosphorus. Add Reef BioFuel at 1 mL per 25 US gal to restart consumption.

Does NeoPhos replace a normal food routine?

No — NeoPhos is a targeted booster for unbalanced ULNS tanks, not a substitute for a balanced feeding routine. It is reserved for advanced reefkeepers actively steering their N:P ratio with precision tests — not a blind additive for a standard tank.